Robert Lemaignen (15 March 1893 – 3 April 1980) was a French European Commissioner.

He was appointed as one of the first French European Commissioners on the first Hallstein Commission from 1958 to 1962.

He did not remain a member of the second Hallstein commission and was succeeded as commissioner by Henri Rochereau.

Lemaignen was responsible for Overseas development.

Lemaignen had previously been the vice-president of the French Employers Federation (with extensive African experience).